/*

  * This file is part of FFmpeg.

  *

  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file
  * replaygain tags parsing
  */
 
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "libavutil/avstring.h"
 #include "libavutil/dict.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/mathematics.h"
 #include "libavutil/mem.h"
 #include "libavutil/replaygain.h"
 
 #include "avformat.h"

 #include "internal.h"

 #include "replaygain.h"
 

 static int32_t parse_value(const char *value, int32_t min)

 {
     char *fraction;
     int  scale = 10000;
     int32_t mb = 0;

     int sign   = 1;

     int db;
 

     if (!value)
         return min;

     value += strspn(value, " \t");

     if (*value == '-')

         sign = -1;
 

     db = strtol(value, &fraction, 0);

     if (*fraction++ == '.') {
         while (av_isdigit(*fraction) && scale) {
             mb += scale * (*fraction - '0');
             scale /= 10;
             fraction++;
         }
     }
 
     if (abs(db) > (INT32_MAX - mb) / 100000)

         return min;

     return db * 100000 + sign * mb;

 }
 

 int ff_replaygain_export_raw(AVStream *st, int32_t tg, uint32_t tp,
                              int32_t ag, uint32_t ap)

 {
     AVReplayGain *replaygain;
 
     if (tg == INT32_MIN && ag == INT32_MIN)
         return 0;
 

     replaygain = (AVReplayGain*)av_stream_new_side_data(st, AV_PKT_DATA_REPLAYGAIN,

                                                         sizeof(*replaygain));

     if (!replaygain)
         return AVERROR(ENOMEM);
 
     replaygain->track_gain = tg;
     replaygain->track_peak = tp;
     replaygain->album_gain = ag;
     replaygain->album_peak = ap;
 
     return 0;
 }
 
 int ff_replaygain_export(AVStream *st, AVDictionary *metadata)
 {
     const AVDictionaryEntry *tg, *tp, *ag, *ap;
 
     tg = av_dict_get(metadata, "REPLAYGAIN_TRACK_GAIN", NULL, 0);
     tp = av_dict_get(metadata, "REPLAYGAIN_TRACK_PEAK", NULL, 0);
     ag = av_dict_get(metadata, "REPLAYGAIN_ALBUM_GAIN", NULL, 0);
     ap = av_dict_get(metadata, "REPLAYGAIN_ALBUM_PEAK", NULL, 0);
 

     return ff_replaygain_export_raw(st,
                              parse_value(tg ? tg->value : NULL, INT32_MIN),
                              parse_value(tp ? tp->value : NULL, 0),
                              parse_value(ag ? ag->value : NULL, INT32_MIN),
                              parse_value(ap ? ap->value : NULL, 0));

 }